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A208485
Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to the number of counterclockwise edge increases.
1
152, 1448, 13800, 131528, 1253608, 11948296, 113880744, 1085412040, 10345202024, 98601453704, 939783162408, 8957194434632, 85372174507240, 813693197494792, 7755414729341352, 73917857257827784, 704520623625326696
OFFSET
1,1
COMMENTS
Column 1 of A208492.
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) - 14*a(n-2).
Empirical g.f.: 8*x*(19 - 28*x) / (1 - 11*x + 14*x^2). - Colin Barker, Jul 03 2018
EXAMPLE
Some solutions for n=4:
..3..2....2..3....1..1....3..1....1..0....1..1....2..1....2..0....1..0....1..3
..3..2....0..1....2..2....3..1....2..1....3..1....1..0....3..1....0..0....2..0
..1..3....2..0....1..1....3..3....1..2....0..2....3..1....2..0....0..3....0..2
..0..1....0..1....0..0....3..1....1..1....1..0....0..2....3..1....1..0....2..1
..0..0....3..0....0..0....1..1....0..0....2..1....0..0....1..2....1..0....1..0
CROSSREFS
Cf. A208492.
Sequence in context: A226365 A085775 A208492 * A364815 A359447 A223397
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 27 2012
STATUS
approved